Thermostat



(HoModeL) T. W. SHEPHERD. THERMOSTAT.

No. 479,849. Patented Aug; 2, 1892.

UNITED STATES THOMAS \V. SHEPHERD, OF

THERM PEABODY, MASSACHUSETTS.

OSTAT.

SPECIFICATION forming part of Letters Patent No. 479,849, dated August 2, 1892. Application filed August 6, 1891. Renewed June 27, 1892. Serial No. 438,085. (No model.)

T0 (0% whom, it may concern:

' Be it known that I, THoMAs W. SHEPHERD, of Peabody, county of Essex, State of Massachusetts, have'inventcd an Improvement in Thermostats, of which the following description, in connection with the accompanying drawings, is a specificatiomlike letters on the drawings representing like parts.

This invention relates to thermostats, and has for its object to improve the means for adjustment,whereby a uniform relative movement will at all times exist between the cooperating parts in any adjusted position.

Another object of this invention is to pro- Vide suitable means for varying the adjustment automatically at regular intervals, for a purpose to be hereinafter referred to.

In accordance with this invention a pivoted contact-arm is moved by the lamina between two adjustable contacts mounted on a preferably toothed sector having its pivotal center coincident or in line with the fulcrum or center of vibration of the lamina. Suitable means are provided whereby the sector may be moved in either direction for the purpose of adjusting the position of the contacts. An indicator actuated by the movement of the sector is also provided to assist in adjusting the contacts, as will be described.

One part of this invention in thermostats therefore consists in a pivoted contact-arm and a lamina to move the same, combined with a sector the pivotal point of which is coincident or in line with the pivotal center of said contact-arm, contacts carried by said sector, and a pivoted indicating-arm actuated by said sector, substantially as will be described.

Another part of this invention consists in the combination, with a pivoted contact-arm and a lamina to move the same, of adjustable contacts and mechanism to automatically move the same at intervals.

Other features of my invention will be hereinafter described, and pointed out in the claims.

Figure 1 represents a face view of a thermostat embodying this invention; Fig. 2, a section on the dotted line a: as, Fig. 1. Figs. 3 and a are a face view and a section, respectively, of a modified form of thermostat; and

Fig. 6 is a simple form of time mechanism to be described.

Referring to the drawings, the back or case A, of suitable shape and construction to carry the various parts, has secured to its face near its upper end, as shown, a preferably perforated case a, in which is placed, as represented, a lamina I), having one of its ends attached to the case a and its other free end attached to a staff or spindle 0, having its bearings at one end in the closed end of the perforated case a and at its opposite end in a step or other suitable bearing 0, having a stud a projecting from its rear side, to be hereinafter referred to. The staff 0 outside of the closed end of the perforated case a (see Fig. 2) has fast to it a contact-arm 0 the free end of which lies between the adjustable contact-screws 5 0, mounted in the posts (Z (1', carried by and insulated from the sector (Z pivoted about the stud c on the back of the step or bearing 0', the said posts passing through aslot (Z in the case A referred to. The sector (Z is moved on its pivot against the action of a spring .9 by a suitable adjusting-screw c, Fig. 1, and the said SGCtOldS preferably toothed to actuate a pinionf on a shaftf', to the outer end of which is made fast an indicating pointer or arm g, which,as herein represented,moves about its pivotal center over the indicatingscale or series of characters 20 on the case A, Fig. 1.

The sector d may be adjusted in either direction by the screw 6 to vary the position of the posts d d and contact-screws 5 6, and the said screws 5 6 may also be adjusted in the posts with relation to each other to regulate the interval between the two extremes of temperature at which it is desired the thermostat should operate. As the sector is moved for adjustment, the arm g will be moved over the scale to to indicate to the operator how many degrees the contacts have been moved. It will be seen by reference to the drawings that the contacts d d move about a center coincident or in line with the pivotal center of the c0ntact-arm 0. Thus into whatever adjusted position the sector and contacts may be moved the movement of the contact-arm with relation to the said contacts remains constant, meaning by this that in whatever adjusted Fig. 5,yet another modification to be described.

position the contacts may be the range of movement of the contact-arm between and with relation to the said contacts due to changes in temperature of a certain number of degrees will always be the same. Again, the indicating-arm g, describing the arc of a circle and being actuated by the sector (1 will always preserve the same relation to the sector in whatever position it may be moved, thus giving at all times a correct guide by which to adjust the contacts for a required temperature.

\Vhen the thermostat is employed for certain uses-such, for instance, as to control the heat of a houseit is desirable to change the adjustment at times, as during the night, in order to maintain the temperature'at a lower point than at other times or during the day. To accomplish this object, the supportingpiece for the contacts, in this instance the sector (Z is acted upon by a cam m, mounted on a shaft m, driven by any suitable time mechanism M, (see Fig. 6,) the movement of the cam by such time mechanism acting to move or vary the position of the contacts with relation to the contact-arm at regular intervals.

Figs. 3 and 4 represent a modified form of thermostat, the adjustment of the sector in this instance being accomplished by a thumbnut on the shaftf, which rotates the pinion o fand moves the sector.

Fig.5 represents yet another modified form of thermostat, in which the rotation of the shaft on, carrying the indicating-arm, acts through a suitable cam face or head m upon a pin or stud n, carried by the sector, to move the same, a spring 3 serving to keep the pin against the cam, as shown.

This invention is not limited to the particular arrangement and construction shown, as the same may be varied.

I claim- 1. In a thermostat, a contact-arm and a lamina to move the same, combined with a movable contact, a cam to move the same, and a time mechanism geared to and to move the said cam, substantially as described.

2. In a thermostat, a pivoted contact-arm and a coiled lamina to move the same, combined with a sector the pivotal point of which coincides or is in line with the pivotal center of said contact-arm, and coil-contacts carried by said sector, and a pivoted indicating-arm actuated by said sector, substantially as described.

3. In a thermostat, a pivoted contact-arm and a lamina to move the same, combined with a sector, contacts carried thereby, a spring acting to move the sector in one direction, and adjusting means to move the sector in the opposite direction, substantially as described.

4. In a thermostat, a staff, a coiled lamina surrounding and to rotate the same, and a contact-arm fast upon said staff at one side of the said lamina, combined with a sector arranged at the opposite side of the said lamina and with its pivotal center coincident with the axis of the said staff, adjustable contacts v carried thereby, and means to move the said sector, substantially as described.

5. In a thermostat, a staff, a lamina to 1'0- tate the same, and a contact-arm fast to one end of said staff, combined with a toothed sector placed at the opposite end of said staff, with its pivotal center coincident with the axis of the staff, contacts carried thereby, a pinion rotated by said sector, and an indicating-arm moved thereby, substantially as described.

6. The back A, case a, alamina therein, and a staff rotated by said lamina, and a contactarm fast on said staff, combined with a sector d and means to move it, contacts thereon to co-operate with said contact-arm, the shaft f, pinion f, indicating-arm g, and scale w, substantially as described.

7. In a thermostat, a contact-arm and a lamina to move the same, combined with a sector b contacts carried thereby between which said contact-arm normally moves, the cam m, acting against and to move said sector, and a time mechanism geared to and to rotate said cam, substantially as described.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

THOMAS W. SHEPHERD.

Witnesses:

FREDERICK L. EMERY, EDWARD F. ALLEN. 

